Python Selenium Webdriver - Changing proxy settings on the fly

This is a slightly old question.But it is actually possible to change the proxies dynamically thru a "hacky way"I am going to use Selenium JS with Firefox but you can follow thru in the language you want.

Step 1: Visiting "about:config"

driver.get("about:config");

Step 2 : Run script that changes proxy

var setupScript=`var prefs = Components.classes["@mozilla.org/preferences-service;1"].getService(Components.interfaces.nsIPrefBranch);prefs.setIntPref("network.proxy.type", 1);prefs.setCharPref("network.proxy.http", "${proxyUsed.host}");prefs.setIntPref("network.proxy.http_port", "${proxyUsed.port}");prefs.setCharPref("network.proxy.ssl", "${proxyUsed.host}");prefs.setIntPref("network.proxy.ssl_port", "${proxyUsed.port}");prefs.setCharPref("network.proxy.ftp", "${proxyUsed.host}");prefs.setIntPref("network.proxy.ftp_port", "${proxyUsed.port}");                  `;    //running script below  driver.executeScript(setupScript);//sleep for 1 secdriver.sleep(1000);

Where use ${abcd} is where you put your variables, in the above example I am using ES6 which handles concatenation as shown, you can use other concatenation methods of your choice , depending on your language.(The SetupScript is a string containing the script to be runned enclosed by ``)

Step 3: : Visit your site

driver.get("https://whatismyip.com");

Explanation:the above code takes advantage of Firefox's API to change the preferences using JavaScript code.

To set a proxy on the fly with Firefox:

def set_proxy(driver, http_addr='', http_port=0, ssl_addr='', ssl_port=0, socks_addr='', socks_port=0):    driver.execute("SET_CONTEXT", {"context": "chrome"})    try:        driver.execute_script("""          Services.prefs.setIntPref('network.proxy.type', 1);          Services.prefs.setCharPref("network.proxy.http", arguments[0]);          Services.prefs.setIntPref("network.proxy.http_port", arguments[1]);          Services.prefs.setCharPref("network.proxy.ssl", arguments[2]);          Services.prefs.setIntPref("network.proxy.ssl_port", arguments[3]);          Services.prefs.setCharPref('network.proxy.socks', arguments[4]);          Services.prefs.setIntPref('network.proxy.socks_port', arguments[5]);          """, http_addr, http_port, ssl_addr, ssl_port, socks_addr, socks_port)    finally:        driver.execute("SET_CONTEXT", {"context": "content"})

Usage:

 driver = webdriver.Firefox() set_proxy(driver, http_addr="212.35.56.21", http_port=8080) driver.get("http://....") set_proxy(driver, http_addr="212.35.56.22", http_port=8888) driver.get("http://....")

To change proxy on the fly with Chrome (work on selenium 3.141.0, key point is driver.start_session(cap)):

   proxy = get_new_proxy()     # x.x.x.x:y      c = {       "proxyType": "MANUAL",       "httpProxy": proxy,       "sslProxy": proxy   }      cap = webdriver.DesiredCapabilities.CHROME.copy()   cap['proxy'] = c   driver.start_session(cap)   try:       b.get('https://whatismyip.com')   except Exception as e:       print(e)

p.s. selenium.webdriver.common.proxy.Proxy.add_to_capabilities() may also be used when specifying proxy (so you do not need to use the c dict above.)